Trailer weight

["Dyane Smith" <sunibey@sisqtel.net>]

Anybody had their truck drop to 15 mph over a 7% grade when they were towing
within their rated weight.

I just got my new trailer.  It was supposed to weigh 5200#, but actually
weighs in at over 6100#.  I've got an old (1989) Ford F-250 with a
heavy-duty towing package that is rated to tow 18,500 GCVW.  The truck and
trailer (empty) together weigh 11, 800.  I've had the truck checked out and
we can't find anything wrong with it.  I'm not in a normally high elevation
(3-4000').  I know Teddy recommends a Freightliner, but the truck is old
because it took me so long to get trailer money together.
 Any ideas?
Dyane